Electronic part with external electrode

Abstract

The present invention is intended to solve the problem of a conventional thermosetting conductive paste with respect to bonding-property between an internal electrode(s) and an external electrode(s) so as to provide a multilayer ceramic electronic part suitable for its mounting on a substrate and for its plating-treatment. The present invention relates to a multilayer ceramic electronic part, characterized in that it has an external electrode(s) formed from a thermosetting conductive paste comprising conductive particles having a high melting point, metal powder having a melting point of 300° C. or less and a resin(s).

Description

TECHNICAL FIELD [0001] The present invention relates to a multilayer ceramic electronic part, in particular to a highly reliable multilayer ceramic electronic part such as a multilayer ceramic capacitor, which is suitable for its mounting on a substrate or for its plating treatment. BACKGROUND ART [0002] A multilayer ceramic capacitor which is one example of multilayer ceramic electronic parts is illustrated in FIG. 1, wherein an external electrode (4) formed on a surface where an internal electrode(s) of a ceramic composite body of the multilayer ceramic capacitor (1) is led out is generally formed by using a fired-type conductive paste or a thermosetting conductive paste according to a method as described below, wherein the ceramic composite body comprises a ceramic dielectric(s) (2) and the internal electrode(s) (3), as alternately layered. [0003] The first method is the one for forming an external electrode (4) by applying a fired-type conductive paste to a surface where an inte...

AI Technical Summary

Benefits of technology

[0014] The thermosetting conductive paste comprises metal powder having a melting point of 300° C. or less in addition to conventional conductive particles having a high melting point, and thus the solid-phase diffusion of the conductive particles in the conductive paste into internal electrode metal can progress even at a low curing temperature of about 80° C. to 400° C., thereby excellent bonding-property between the internal electrode(s) and the external electrode(s) can be obtained.

Problems solved by technology

However, a capacitor having an external electrode(s) obtained by the first method above has, for example, the problem of poor plating-adhesion due to the floating of glass, because of the diffusion of the glass-frit component in the conductive paste into the inside of a capacitor element when the capacitor is fired at an elevated temperature, and the problem of the occurrence of cracks when the capacitor is mounted with solder on a substrate.

Furthermore, it has problems concerning the reliability of capacitor performance.

For example, due to the infiltration of a plating solution into a sintered body in the plating-treatment, the electric capacitance is lower than a designed value, and / or the insulation resistance is deteriorated.

However, because of its low curing temperature, the metal-to-metal solid-phase diffusion of the conductive particles (such as silver powder) in the conductive paste into the internal electrode(s) can not progress, and thus the junction of the internal electrode(s) with the external electrode(s) is poor, thereby its designed electrical properties such as electric capacity can not be obtained, and thus the resultant capacitor is poor in the reliabilities.

Furthermore, a capacitor having an external electrode(s) formed by the third method, wherein the thermosetting conductive paste containing the pyrolytic organometallic material(s) is used, has such problems as the insulation deterioration for its moisture-resistible duration of life and the pot life of the paste is shortened, due to silver acetate and amine added to the paste.

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